1. Field of the Invention
This invention relates to metal-thermoplastic-metal laminates comprising a metal layer laminated to each side of a thermoplastic core layer selected from the group consisting of partly crystalline polyamides and polyesters. These laminates have an improved combination of critical properties required for use in construction applications.
2. Description of the Prior Art
Metal-thermoplastic-metal laminates and processes for their preparation are known. See, for example, Bugel et al., U.S. Pat. Nos. 3,382,136; Zunich et al., 3,352,742; and Pohl et al., Modern Plastics, 41 (7 March), 119-124 (1964).
The laminates described in the above-noted references as well as other prior art laminates, however, are, in general, limited in their applications, particularly when contemplated for use as construction panels where the combination of good dimensional stability under engineering loads at elevated temperatures (high heat-distortion temperatures), low thermal expansivity (low coefficient of linear thermal expansion) and good recovery from flexural deflection (low inelastic ratio) are necessary properties of a light-weight laminate.